First hollow stem update 02/19/15

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Since April 2016, I have served as the Small Grains Extension Specialist at Oklahoma State University. My research and extension efforts focus on delivering science-based recommendations in order to increase small grains production and profitability for stakeholders throughout Oklahoma and the southern Great Plains.

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First hollow stem is the optimal time to remove cattle from wheat pasture (full explanation). We measure first hollow in our September-sown wheat forage plots at Stillwater each year, and the warm temperatures have caused first hollow stem to advance ahead of schedule this year. The small grains extension crew split ten stems from each of the 56 lines tested in our program yesterday and Sy Llano, WB-Cedar, WB-Redhawk, and a few experimental lines were all at first hollow stem. Early varieties such as Gallagher, Greer, Everest, WB4458, TAM 114, and Brawl CL Plus are not far behind. A full listing of first hollow stem measurements are included in the table at the end of this blog. We will take another set of measurements the first of next week and report the results on this blog.

The numbers reported from Stillwater are likely behind those being observed in southern Oklahoma and ahead of those observed in northern Oklahoma. Jim Johnson with the Noble Foundation reported seeing quite a bit of first hollow stem in early varieties last week.

Probability of first hollow stem for early maturing wheat varieties as estimated on 02/19/15. Red areas indicate there is at least 50% likelihood that early-maturing wheat varieties have reached first hollow stem in the shaded area.

One week projection of first hollow stem for early-maturing wheat cultivars 02/19/15

The First Hollow Stem Advisor on the Oklahoma Mesonet indicates that early varieties in southern Oklahoma are likely past first hollow stem and that early varieties in central Oklahoma will reach this point within a week.

Keep in mind the one week projection uses historical weather conditions which are slightly above our current forecast. Cooler than normal conditions will not last long and wheat can grow anytime average daily temperature is above 32F. So, my advice is to move cattle off of wheat pasture in southern Oklahoma yesterday, start moving them off of wheat pasture in central Oklahoma today, and move cattle off wheat pasture in northern Oklahoma next week.

First hollow stem measured in wheat sown 09/16/2014 at Stillwater, OK. Varieties at or past first hollow stem (>1.5 cm of hollow stem) are shaded in red.